SU542105A1 - Device for measuring the coefficient of thermal expansion - Google Patents

Description

(54) DEVICE FOR MEASUREMENT OF THERMAL COEFFICIENT

EXTENSIONS

winding of the first relay and the other input register of the eator, respectively, through a zero-indicator and voltage divider. The scale setting unit is connected to the heating speed setting unit, and the first output of the first relay, the first input of which is connected to the output of the memory unit, is connected to its control input. The inputs of the memory unit and the comparator unit, to the output of which the winding of the second relay is connected, are connected respectively to the second and third outputs of the first relay, the second and third inputs of which are connected to the first and second outputs of the speed extension sensor, the third output of which and the input of the first differentiating element connected respectively to the input and output of the second relay.

This allows you to increase the speed and accuracy of the device.

The drawing shows a block diagram of the device.

The device contains a temperature meter 1, a comparator unit 2, a first relay 3, a thermostat 4, a sample extension speed sensor 5, a first differentiating element 6, a regulating unit 7, a memory unit 8, a zero-indicator 9, a setting unit for heating rate 10, a setting unit scale 11, the second relay 12, the second differentiating element 13, the voltage divider 14 and the recorder 15.

The device works as follows.

At the moment of switching on, the heating rate setting unit 10 delivers through the regulating unit 7 a strictly defined power to the heater of the thermostat 4. The sample begins to lengthen, and at the output of sensor 5 an electrical signal appears in the form of a single-hump curve. The vertex of a single-hump curve is the inflection point of the acceleration curve.

To determine the point in time at which the signal from sensor 5 reaches its maximum, its output is connected to the input of differentiating element 6 via the contacts of the relay 3, controlled by the signal of the comparison unit 2, and to the input indicator 9. Thus, the null indicator 9 is triggered when the signal at the output of sensor 5 reaches the maximum value. The signal from the output of the null organ triggers a relay 12, which destroys its contacts between the sensor 5 and the comparison units 2 and the memory 8 and closes the circuit between the memory unit 8 and the scale setting unit 11. The last, affecting the heating speed setting unit 10, raises the power to the set heating rate, after which the sample begins to heat at a given speed. In this case, the adjustable parameter does not depend on the shape and size of the sample.

The temperature is differentiated using two thermal elements 13 with different inertia. The signal from the differentiating element 13 through the voltage divider 14 is fed to the input of one of the coordinates of the recorder 15, to the input of the second coordinate of which the signal comes from the temperature meter 1.

In order to avoid a false failure of the relay 12, the differentiating element 6 is connected to the output of the sensor 5 via the contacts of the relay 3, which turns on only after the appearance of the signal at the output of the comparison unit 2.

The technical and economic effect is that the overall accuracy of the measurement is due to more accurate heating, as well as the ability to measure on large specimens while maintaining the sensitivity of the sensor.

Increased productivity is achieved by reducing the time required for processing the results, for determining and introducing corrections, and also due to the absence of strict requirements for the sample size.

Claims (1)

Invention Formula A device for measuring the thermal expansion coefficient, comprising a series-connected heating rate setting unit, a control unit, a thermostat and a temperature meter connected to one of the recorder inputs, characterized in that, in order to improve the speed and accuracy of the device, it contains a sample elongation speed sensor , the first and second differentiating elements, a null indicator, a comparison unit, the first and second relays, a voltage divider, a scale setting unit and a memory block, and outputs The first and second differentiating elements are connected to the winding of the first relay and another input of the recorder, respectively, via a null indicator and voltage divider, the scale setting unit is connected to the heating speed setting unit, and the first output of the first relay is connected to its control input connected to the output of the memory unit; the inputs of the memory unit and the comparator unit, to the output of which the winding of the second relay is connected, are connected respectively to the second and third outputs of the first relay, the second and third inputs of which are connected to the first and second outputs of the speed sensor, the third output of which is the first differentiating element connected respectively to the input and output of the second relay.